I. Field of the Invention
The present invention relates generally to the fields of molecular biology and medicine. More particularly, it concerns methods and compositions involving microRNA (miRNAs) molecules and disease treatment. Certain aspects of the invention include applications of miRNA therapy for diseases or conditions that involve neovascularization and/or angiogenesis.
II. Background
Pathologic neovascularization refers to the proliferation of blood vessels in tissue not normally containing them, or proliferation of blood vessels of a different kind than usual in a tissue. It includes angiogenesis in tumor growth, diabetic retinopathy, haemangiomas, arthritis, and psoriasis to name a few.
Angiogenesis is the process of forming new blood vessels from pre-existing capillaries. Angiogenesis is tightly regulated and normally does not occur except during development, wound healing, and the formation of the corpus luteum during the female reproductive cycle. This strict regulation is manifested by a balanced production of positive and negative factors, which keep angiogenesis in check. However, this balance becomes abrogated under various pathological conditions, such as cancer, diabetes, and age-related macular degeneration (AMD), resulting in the growth of new blood vessels. It is now well accepted that the progressive growth and metastasis of many solid tumors and loss of vision with diabetes are dependent on the growth of new blood vessels.
Vascular diseases of the eye and tumors of the central nervous system, such as retinoblastoma and primitive neuroectodermal tumors (PNETs), have significant neovascular components. Some tumors of the central nervous system and ocular vascular diseases share similar pathogenesis having a choroidal neovascularization and/or retinal neovascularization component.
Vascular diseases of the eye comprise a major cause of blindness. These diseases include various retinopathies and macular degeneration. Existing treatments include laser ablation of various regions of the retina; vitrectomy or removal of the cloudy vitreous humor and its replacement with a saline solution; and administration of antioxidant vitamins E and C, but none of these methods can cure the disease. Further, existing invasive treatment methods often result in significant loss of vision. Non-invasive methods of treatment are experimental and have not been shown to substantially reduce the risk of blindness or loss of sight.
There is a need for additional compositions and/or methods for treatment of diseases associated with neovascularization and angiogenesis.